Warning! This article contains spoilers for The Eternaut.Since The Eternaut begins with a mysterious apocalyptic event, many viewers may be curious about how the world nearly ended in the Netflix series. Based on Héctor Germán Oesterheld and Francisco Solano López's graphic novel of the same name, The Eternaut opens with toxic snow falling from the sky. Many humans perish in the show's opening moments itself because they fail to realize how deadly the snow can be if it comes in with one's skin.

Others eventually understand that there is more to the weather anomaly than meets the eye and protect themselves from it by either staying indoors or going out with their bodies fully covered. Although the snowfall eventually stops in the main characters in The Eternaut comes up with a convincing theory that explains the phenomenon.

The Eternaut's Toxic Snowfall Explained

The Snowfall Was Caused By A Shift In The Earth's Magnetic Field

The surviving humans initially struggle to understand what is happening around them but are able to deduce that the apocalypse has something to do with the snow. An electrical engineer, Favalli, later theorizes that the toxic snowfall might have something to do with a major shift in the Earth's magnetic field. He associates the event with the Van Allen belts, which are zones of charged particles trapped in the Earth's magnetic field. Since the belts are 1,000 to 60,000 km above the Earth’s surface, they cannot directly affect anyone on the planet.

Favalli's theory ultimately makes a lot more sense when, after the snow stops falling, comes confirm that the poles have flipped

According to Favalli's theory, however, the Earth goes through a dramatic shift in magnetic fields when its poles are reversed by an unknown force. This switch between the poles temporarily weakens the planet’s magnetic shield, allowing cosmic radiation from the Van Allen belts to bind with snow and fall toward the surface. The radiation eventually loses its strength the closer the snow particles reach the surface. However, the radiation is still harmful enough to kill anyone who comes in with the falling snow.

Favalli's theory ultimately makes a lot more sense when, after the snow stops falling, comes confirm that the poles have flipped. It must be noted that even though there is a semblance of science in the show's speculations surrounding shifting poles and radiations from the Van Allen belt, most of its ideas are rooted in pseudoscience. While poles can certainly shift, radiation from the Van Allen belts can never make it to the surface. However, given how The Eternaut later confirms the involvement of alien forces, one can add another layer to Favalli's theory to make it more plausible.

The Deadly Snowfall Was Caused By Aliens In The Eternaut

It Was The First Stage Of The Alien Attack

The Eternaut avoids giving away the details surrounding the central alien species' overarching plan and motives. However, it seems evident that the aliens planned to attack humans in several different stages. The snowfall seems to serve as the first phase of the invasion, where the aliens intentionally trigger a shift in the planet's poles to destroy almost all means of transportation and communication among humans. Once that is out of the way, the aliens send out giant beetle-like creatures to further weaken human resistance.

As established in The Eternaut's final arc, the aliens also possess mind-controlling abilities that allow them to keep several humans under their control. While it remains unknown what they want from humans, it seems possible that, through mind control and manipulation, they hope to turn the surviving humans into soldiers and use them to combat an even greater threat. Hopefully, The Eternaut season 2 will delve deeper into these ideas and make things a little less ambiguous.